Dependence on Strain Rate and Temperature Shown by Yield Stress of Uranium Dioxide

Abstract

Specimens of polycrystalline UO2 were strained in compression at constant strain rate from 0.05 to 10.0/min and at temperatures ranging 900°C2, 000°C. The experimental results revealed characteristic yield point, and the yield stress varied with strain rate and temperature. The present data, obtained at strain rates higher than currently adopted, showed greater sensitivity on strain rate and a higher activation energy for yield flow.
The data are discussed in their relation to the mechanism that controls the yield strength. The yield strength at high strain rate would appear to be controlled primarily by the peierls stress.